Abstract

Biodiesel, an alternative fuel consisting of the alkyl monoesters of fatty acids from vegetable oils or animal fats, has been recognized recently as an environment friendly fuel for diesel engines. In the present study an investigation on engine performance of a compression ignition (CI) engine has been carried out under the steady state as well as transient conditions. The parameters required for the model have been obtained from a turbocharged, 4 cylinders, 4 stroke, and water cooled engine. The physical and chemical properties of the biodiesel and its blends were tested according to EN ISO 3675:1998 and EN ISO 3104:1996 standards. For the test rapeseed oil biodiesel and its blends with normal diesel were used at 0%, 20%, 50%, and 100% of biodiesel blending. The series of transient cycles studied included speed profile changes of 800-1200rpm, 1200-1500rpm, 1500-1800rpm and 1800-2200rpm over a time period of 4 seconds. The model was validated by experimental results and shows 5-10% deviation in engine performance parameters for steady state operation. The results show that the CI engines running on biodiesel shows reduction in brake power by 14%. The brake specific fuel consumption (BSFC) and thermal efficiency of the CI engine running on 100% biodiesel increases by 8.5% and 4.5% during transient conditions as compared to normal diesel fuel operation respectively. The viscosity of the biodiesel has been shown to affect the performance of the engine running on biodiesel.